Hydraulic mechanism



HYDRAULIC MECHANISM Original Filed June 18, 1941 2 Sheets-Sheet 1 n AlIll Ill/ll FIG.

mmvroa. JAY D. JOHNSON Feb. 11, 1947. J. D. JOHNSON 2,415,498

HYDRAULIC MECHANISM Original Filed June 18, 1941 2 Sheets-Sheet 2 FIGINVENTOR. JAY D. JOHNSON Patented Feb. ll, 1947 STATES.

HYDRAULIC MEG Jay D. Johnson, Peoria, Ill., assignor to .lohn

Deere Tractor Company, Waterloo, Iowa, a corporation of Iowa Originalapplication June 18, 1941, Serial No. 398,539. Divided and thisapplication March 13, 1943, Serial No. 479,130

The present invention relates generally to hydraulic mechanisms of thetype used for control- 1ing the'action of hydraulic lifting cylinders,such as are used on tractor power lifts, dump trucks,

generally to a novel method of supporting power.

lift mechanism and of supplying power thereto. More specifically, it isan object of my invention to provide a novel and improved valve and pumpassembly, which is exceedingly compai'lt but efficient and durable inoperation. A further specific object relates to the provision of meansfor mounting the valve and pump assembly on the governor housing of atractor, with means provided for taking power from the governor shaft todrive the pump. Still another object relates to the provision of meansfor venting the reser- 9 Claims. (01. 103-1) opening 82 in the end ofthe housing 5 and secured to the housing by bolts l3. The end plate I!is provided with an aperture it, through which extends the drive shaft 9a short. distance beyond the end plate II. The shaft 9 is driven througha drive gear l5, which is rigidly mounted on the shaft by means of asuitable key l6, and is secured against axial movement by the ballbearing Ill on one side and by a snap ring i! voir of the valve housingin such manner that any oil or oil vapor which tends to escape from thevent in the reservoir is conducted to the tractor governor housing.

These and other objects and advantages of my invention will be apparentto those skilled in the art after a consideration of the followingdescription, in which reference is had to the drawings appended hereto,in which Figure 1 is an elevational view of the valve casing of ahydraulic power lift mechanism embodying the principles of my invention,showing the manner of mounting the valve casing on the governor housingof a tractor, a portion of the casing being broken away to show some ofthe valve mechanism in section;

Figure 2 is a section taken along a line 2-2 in Figure 1, showing themeans for venting the hydraulic reservoir;

Figure 3 is a plan view of the valve and pump mechanism, and thegovernor housing, a portion indicated at 3-3 in Figure 1, being shown insection in Figure 3. Figure 3 is drawn to a slightly smaller scale thanare Figures 1 and 2.

Referring now to the drawings, reference numeral 5 indicates, in itsentirety, a vehicle such as a tractor or'the like, on which is mounted asuitable drive housing 6, in this embodiment a governor housing. Thehousing 6 is provided with a suitable base flange 1 secured to thevehicle 5 by bolts 8. A drive shaft 9 is disposed within the housing 6,one end of said shaft being rotatably supported in a ball bearing "I,which is carried in an end plate II, which fits snugly over an or otherconventional means on the other side.

The gear 15 meshes with an engine driven gear l8 within the vehiclebody, which may be either on the'crank shaft or on the camshaft of thetractor engine, or on any other suitable shaft.

The governor mechanism, which maintains constant the speed of thetractor eng-ine, as is well-known to those skilled in the art, has beenomitted from the drawings, since it forms no part of the presentinvention, and is specifically disclosed'and claimed in Patent2\,l59,283, granted to McCormick, May 23, 1939, but it is understoodthat the shaft 9 is adapted to drive the governor and/or other parts'ofthe vehicle. For example, a shaft l9 supported in a bearing 20 in thegovernor housing -6 extends outwardly to drive a part of the engine,such as the cooling fan.

The outer end of the governor shaft 9 is splined, a indicated at 25, todrive pumping means in the form of a pair of intermeshing pump gears Z3,21. The drive gear 26 is fixed to the shaft 9 by the splines 25 and thedriven gear 21 is supported for rotation about the axis of a stub shaft28, which is journaled at opposite ends, respectively, in recesses 23,30 in the end platev H and in a flat wing portion 3! of a control orvalve casing, indicated generally by reference numeral 32. The gears26,11 are enclosed within a gear housing 35, which is annular in form,that is to say, it extends'peripherally around the gears in closeproximity to the ends of the teeth to maintain the pressure of the pump,but is open along each side thereof. However, by virtue of the positionof the gear housing 35 rigidly sandwicl'ied in between the end plate I Iand the wing portion 3!, the latter two elements serve as side walls forthe pump housing. The pump housing is clamped between the end wall H andthe wing portion 3| by means of several bolts 36, which extend throughsuitable aligned apertures in the assembled parts and are threaded intothe end plate H. Other bolts 31 extend through aligned openings in thewing portion 3|, gear housing 35,

generally by reference gather in fluid retaining relation.

The valve casing 32 comprises a generally rectan'gular reservoir portion45, which lies along one side of the drive or governor housing 5, theflat wing portion 3| extending generally perpendicular to one side ofthe reservoir portion 45 in juxtaposition to the pump housing 35 asexplained above. The flat wing portion 3| supports the reservoir portion4|! through the bolts 35, 31 on the end plate II and drive housing 5. Noother support for the valve casing 32 is required, although such may beprovided if so desired.

The reservoir portion 40 is hollow to provide a fluid reservoir 4|, abranch 42 of which extends through the wing portion 3| in communicationwith a port 43 in the inner wall of the wing portion 3|. This port 43 isdisposed in register with the inlet passage 44 in the pump housing 35.The gears 25, 21 rotate in the direction indicated by the arrows inFigure 1 and trap the oil or other hydraulic fluid between the teeth ofthe gears and the housing 35 and carry the fluid around to the dischargepassage 45 in the pump housin 35.

A port 45 is disposed in the inner face of the wing portion 3| inregister with the discharge passage 45 and is connected with a highpressure duct 41 extending through the wing portion 3| inwardly to valvemechanism, indicated numeral 55, within the valve casing 32.

Inasmuch as the valve mechanism per se forms no part of the presentinvention, it will be but briefly described herein, as it is fullydescribed in the above-mentioned co-pending application ofwhich this isa division. The high pressure discharge duct 41 extends generallyhorizontally and intersects a vertical bore 5| in the valve casing 32.At its upper end, the bore 5| communicates with the reservoir 4|, and atits lower end below the duct 41, it opens into a cylindrical valvechamber 52, formed in an extension 53 in the bottom of the casing 32.The lower end of the valve chamber 52 is tapped to receive a reducer 4554, to which a delivery tube or conduit 55 is coupled in any suitablemanner. The delivery conduit 55 is extended to any suitable powernnitsuch as a piston and cylinder (not shown). A check valve 55 of thepoppettype is adapted to close upwardly against the valve seat 51 forclosing off communication between the delivery conduit 55 and thevertical bore 5|. The check valve 55 is urged upwardly toward a closedposition by means of a light spring 58, which seats in a bore 59 in thereducer 54 and encircles a guide lug on the check valve 55. The stem 5|of the check 'valve 55 extends upwardly through the vertical bore 5| andis received within a socket 52 in the lower end of a manually controlledpiston valve, indicated in its entirety by the reference numeral 53.This manual valve comprises a plunger shaft 54 slidable in a bearing lug55 secured to an internal wall 55 in the valve casing 32, and the shaft54 extends upwardly out of the casing 32 through a suitable packinggland 51. The lower end of the manually controlled plunger shaft 54carries a cylindrical piston valve 53, which is engageable with a stop59 in the form of a collar or flange rigidly fixed to the check valvestem 5|, but the valve plunger 54 may move upwardly relative to thecheck valve 55, and the latter may in turn move downwardly relative to Ithe manually controlled valve 50.

The valve plunger 54 is manually controlled by means of a hand lever 15pivotaily connected by means of a pin 1| to a standard 12 bolted to thetop of the valve casing 32 by bolts 13. The hand lever 1|) is swingablevertically on the pivot pin 1| and is connected'with the upper end ofthe plunger shaft 54 through a toggle link 14.

, When the control lever 10 is raised, to the position shown in solidlines in Figure l, the piston valve 55 is held in the upper portion ofthe ver tical bore 5| above the high pressure supply duct 41, thuspreventing the oil from flowing upwardly into the reservoir 4|, butproviding a path for the oil to flow downwardly through the verticalbore 5|. The pressure of the oil forces the check valve 55 to opendownwardly against the yielding action of the spring 55 and the oil thenflows downwardly through the reducer fitting 54 into the deliveryconduit 55 leading to the lifting cylinder.

By moving the handle 10 downwardly, the piston valve 58 is moveddownwardly in the verticalbore 5| into the lower portion of the latter.below the supply duct 41. Thisopens the upper portion of the verticalbore 5| above the supply duct 41, and since the plunger shaft 54 issmaller in diameter than the diameter of the bore 5|, the oil readilyflows upwardly through the latter into the reservoir 4| thus relievingthe pressure in the supply duct 41. .This causes the spring 58 to closethe check valve 55, looking the oil in the delivery conduit 55, but byforcing the plunger shaft 54 downwardly still further, the piston valve58 engages the stop 55 on the check valve stem 5| and further downwardmovement of the handle l0 forces the check valve 55 open, thus allowingthe trapped oil in-the power lift cylinder and the delivery conduit 55to escape upwardly past the check valve 55, but since the piston valve55 in this position blocks the vertical bore 5|, as indicated in dottedlines in Figure l, the oil must follow a by-pass, the upper and lowerports of which are indicated by reference numerals 15 15, respectively.

Inasmuch as the governor shaft 9 runs at a more or less constant speed,the oil is delivered to the supply duct 41 at a substantially constantrate. Therefore, whenever the oil is not being conducted to the cylinderto lift the load, it must be conducted back to the reservoir 4|.Ordinarilir. this is accomplished by leaving the handle 10 in its lowerposition as indicated in dotted -by reference numeral 11 connected to avertical passage 13, which communicates with the supply duct 41. Thismechanism, which includes a conventional spring loaded pressure reliefvalve, can be of any conventional construction, and is shown in detailin my co-pending' application, and it is therefore consideredunnecessary to describe the same herein in detail, as it forms noimportant part of the present invention.

The reservoir 4| is provided with a vent in order to insure that thepressure within the reservoir does not rise and fall and thus interferewith movements of the control handle"). This vent is in the form of ashort duct extending upwardly through the top of the valve casing 32from the reservoir M'. This short duct 80 is dissaid portion servingsaid pump gears, said end plate serving as the opposite housing wall forthe gears, each of said housing walls having a rerespectively, areinterconnected by a groove 87 formed in the bottom of the supportingstandard Thus, whenever a slight pressure tends to build up within thereservoir M, it is exhausted through the duct BI), groove 81, duct 83,and opening 84, into the governor housing 6. The reason for venting thereservoir (ii into the. governor housing, rather than directly to theatmosphere, is that usuallyv there is oil vapor in the reservoir M,which would escape and condense on the outside of the casing 32. Byventing'this oil vapor into the governor housing, the oil can condenseand drop into the oil supply within the housing, without harm.

The oil within the reservoir M can be replenished through a suitablehole 9%, closed by a plug 9!. Access to the valve mechanism is obtainedby removing a plate e2 secured by bolts 93.

I claim:

1. In hydraulic mechanism, a control casing having valve mechanismtherein and a vent therein interconnecting said passage and said ventopening. a

2. In combination, a governor housing, a removable end plate securedthereto and having an aperture therein, a governor shaft in said housingand extending through said aperture, bearing means in said end plate inwhich said shaft is journaled, a hydraulic control casing having anassociated pump housing attached thereto, means for securing saidcontrol casing and said pump housing to said end plate, means in saidcontrol casing for controlling the flow of hydraulic fluid to and fromsaid casing, and pumping means in said pump housing for supplying fluidto said control casing and adapted to engage the outer end of saidgovernor shaft to be driven thereby.

3. In combination, a governor housing, an end plate detachably securedthereto, a governor shaft in said housing, bearing means supported onsaid end plate in which said shaft is journaled, said shaft extendingoutwardly through a suitable aperture in said end plate, a pair ofintermeshing pump gears, one of said gears being mounted on .the outerend of said governor shaft, the other bein mounted on a supportingshaft, a valve mechanism for controlling the flow of fluid from saidpump gears, a control casing for said mechanism having a portion lyingagainst one side of said gears and serving as a housing wall therefor,there being supply and discharge ducts in cess to receive one end ofsaid gear supporting shaft, an annular housing member disposed bea tweensaid governor housing and said control casing and having an openingadapted to receive said gears, and bolts for clamping said end plate,said annular housing, and said control casing rigidly together.

4. In hydraulic mechanism, a drive housing, an

end plate therefor, a drive shaftin said housing extending outwardlythrough an aperture in said end plate and supported for rotationtherein, a

pump housing disposed in juxtaposition to'said end plate, pumping meansin said pump housing and attached to said drive shaft to receive powertherefrom, said pump housing having intake and discharge means servingsaid pump means, a control casing having a flat wing portion adapted tolie in juxtaposition to said pump housing and having inlet and dischargepassages in register with said intake and discharge means, valvemechanism in said casing for controlling the fluid output from saidpumping means, and means for clamping said end plate, said pump housingan said control casing rigidly together;

5. In hydraulicmechanism, a drive housing, an end plate therefor, a'drive shaft in said housing extending outwardly through anaperture insaid end plate and supported for rotation therein, a pump housingdisposed in juxtaposition to said end plate, pumping means in said pumphousing and attached to said drive shaft to receive power therefrom,said pump housing having intakeand discharge means serving said pumpmeans, a control casing including a fluid reservoir disposed along aside of said drive housing and having a flat wing portion projectingfrom a wall thereof and adapted to lie in juxtaposition to said pumphousing and having inlet and discharge passages in register with saidintake and discharge means, valve mechanism in said casing forcontrolling the flow of fluid in said passages, and means for clampingsaid end plate, said pump housing and said control casing rigidlytogether.

6. In hydraulic mechanism, a drive housing, a

drive shaft therein, a pump housing disposed in v juxtaposition to saiddrive housing and having pumping mechanism connected to said drive shaftand inlet and discharge ports, a control casing having a portion lyingin juxtaposition to said pump housing and having inlet and dischargepassages disposed in register 'with said housing ports, valve means insaid casing for controlling the flow of fluid in said passages, saidcasing also including a reservoir connected with said inlet passage anda vent passage connected with the upper portion of said reservoir andcome municating with said drive housing.

7. In hydraulic mechanism, a drive housing, an end plate therefor, adrive shaft in'said housing extending outwardly through an aperture insaid end plate andsupported for rotation there in, a pump housingdisposed in juxtaposition 'to said end plate, pumping means in said pumphousing andattached to said drive shaft to receive power therefrom, saidpump housing having intake and discharge means serving said pump means,valve mechanism for controlling the flow of fluid from said pumpingmeans, a valve casing for said valve mechanism including a reservoirportion disposed along a side of said drive housing and having a flatwing portion projecting from a wall thereof and adapted to having intakeand discharge passages in register with said intake and discharge meansand connected with said reservoir and said valve mechanism within saidcasing, and a vent pas-- sage leading from the upper portion of saidreservoir portion through said flat wing portion, the latter having anopening disposed in register with an aperture in said drive housing, andmeans for clamping said casing and said pump housing rigidly to saidendplate.

8. In hydraulic mechanism, a valve casing having valve mechanism and areservoir therein for hydraulic fluid, the flow of which is controlledby said mechanism, said casing also having a vent opening in the upperportion thereof for maintaining the pressure in said casing atsubstantially atmospheric to prevent pressure interference with saidvalve mechanism, a supporting structure having a a fluid receivingchamber therein, a portion of said casing being adapted to be secured tosaid supporting structure, and duct means connecting said vent openingwith said casing portion and adapted to register with an aperture insaid supporting structure to conduct any vapor from said fluid to saidchamber. 9. In hydraulic mechanism, a, valve casing having valvemechanism and a reservoir therein for tially atmospheric to preventinterference with said valve mechanism, a housing, drive means in saidhousingior driving said pumping means, an

, extension on said casing, bolt means for rigidly securing said casingextension to said housing, said extension having duct means extendingfrom the upper portion of said reservoir adjacent said vent opening andadapted to register at the opposite end with an aperture in saidhousing, and a part secured to said upper portion of the reservoir andhaving a duct formed therein interconnecting said duct means and saidvent opening to equalize the pressure inside and outside the reservoirto avoid pressure interference with said valve mechanism whileconducting any vapor from said fluid to collect the condensate thereolin said housing.

JAY D. J OHNSON.

REFERENCES CITED The following references are of ,record in the tile ofthis patent:

hydraulic fluid, pumping means for supp ying a flow of fluid to saidvalve mechanism to be controlled thereby, said casing also having a ventopening in the upper portion thereof for maintaining the pressure insaid casing at substan- UNI'I'ED STATES PATENTS Number Name Date2,107,152 Huber Feb. 1, 1938 2,324,866 Mott July 20, 1943 2,340,474Johnson Feb. 1, 1944 1,470,804 Buckingham Oct. 16, 1923 2,149,969Lattner Mar, 7, 1939 2,264,616 Buckbee Dec. 2, 1941 2,310,078 HermanFeb. 2, 1943 2,107,760

McCormick et al. Feb. 8, 1938

